Труды сотрудников ИВМ СО РАН

[Text] / S. Muhlbachler [et al.] // COMPARATIVE RECONNECTION STUDIES AT THE SUN AND IN PLANETARY MAGNETOSPHERES. Ser. ADVANCES IN SPACE RESEARCH : PERGAMON-ELSEVIER SCIENCE LTD, 2002. - Vol. 29: D0 1-E3 1 Symposium of COSPAR Scientific Commission D held at the 33rd COSPAR Scientific Assmbly (JUL, 2000, WARSAW, POLAND), Is. 7. - P1113-1118, DOI 10.1016/S0273-1177(02)00033-9. - Cited References: 14 . - ISBN 0273-1177РУБ Engineering, Aerospace + Astronomy & Astrophysics + Geosciences, Multidisciplinary + Meteorology & Atmospheric Sciences

Аннотация: Magnetic reconnection is a process which allows topological different magnetic fields to interconnect. Thus, in magnetospheric context, reconnection is strongly associated with substorm phenomena. Because many observations show a difference between the pressure parallel and perpendicular to the magnetic field, it is reasonable to study the reconnection mechanism for the set of equations, involving a pressure tensor. Existing theoretical work for isotropic weak reconnection is extended for anisotropic theory. In particular, the reconnection associated discontinuities as the Alfven discontinuity, the slow shock, and the contact discontinuity are generalized for anisotropic pressure. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.


Доп.точки доступа:
Muhlbachler, S.; Biernat, H.K.; Semenov, V.S.; Farrugia, C.J.; Vogl, D.F.; Erkaev, N.V.; Еркаев, Николай Васильевич

[Text] / V. V. DENISENKO, S. S. ZAMAY // Planet Space Sci. - 1992. - Vol. 40, Is. 7. - P941-952, DOI 10.1016/0032-0633(92)90134-A. - Cited References: 47 . - ISSN 0032-0633РУБ Astronomy & Astrophysics

Аннотация: A model of the ionosphere as a global conductor is used to examine synchronous variations of electric fields and currents at high and low latitudes. The special form of a boundary value problem and a multigrid numerical method permit investigation of auroral field penetration to the equator. A model of field-aligned currents and conductivities for expansion and recovery phases of a substorm are suggested, which are in accordance with empirical models and with theory of field-aligned current dynamics. Electric field distributions near the equator, which were obtained as a result of calculations, are in accordance with observations during substorms. It is shown that the contribution of high latitude sources to low latitude electric fields and currents during quiet-time periods is comparable with that given by dynamo fields. The nature of the post-sunset peak of the zonal electric field at the equator and seasonal variations of this peak are explained.


Доп.точки доступа:
ZAMAY, S.S.; Денисенко, Валерий Васильевич

/ M. Kubyshkina [et al.] // Geophys. Res. Lett. - 2018. - Vol. 45, Is. 9. - P3760-3767, DOI 10.1002/2017GL076268 . - ISSN 0094-8276
Аннотация: We analyze two substorm onset lists, produced by different methods, and show that the (Bx·vz) product of the solar wind (SW) velocity and interplanetary magnetic field (IMF) components for two thirds of all substorm onsets has the same sign as IMF Bz. The explanation we suggest is the efficient displacement of the magnetospheric plasma sheet due to IMF Bx and SW flow vz, which both force the plasma sheet moving in one direction if the sign of (Bx·vz) correlates with the sign Bz. The displacement of the current sheet, in its turn, increases the asymmetry of the magnetotail and can alter the threshold of substorm instabilities. We study the SW and IMF data for the 15-year period (which comprises two substorm lists periods and the whole solar cycle) and reveal the similar asymmetry in the SW, so that the sign of (Bx·vz) coincides with the sign of IMF Bz during about two thirds of all the time. This disproportion can be explained if we admit that about 66% of IMF Bz component is transported to the Earth's orbit by the Alfven waves with antisunward velocities. ©2018. American Geophysical Union. All Rights Reserved.

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Держатели документа:
Earth Physics Department, Saint Petersburg State University, Saint Petersburg, Russian Federation
Institute of Computational Modelling, Federal Research Center “Krasnoyarsk Science Center SB RAS”, Akademgorodok, Russian Federation
Department of Applied Mechanics, Siberian Federal University, Krasnoyarsk, Russian Federation
Finnish Meteorological Institute, Helsinki, Finland
Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, United States

Доп.точки доступа:
Kubyshkina, M.; Semenov, V.; Erkaev, N.; Gordeev, E.; Dubyagin, S.; Ganushkina, N.; Shukhtina, M.

/ D. B. Korovinskiy [et al.] // Phys. Plasmas. - 2018. - Vol. 25, Is. 9, DOI 10.1063/1.5046175 . - ISSN 1070-664X
Аннотация: The problem of the magnetohydrodynamical stability of bent magnetotail current sheets is considered by means of 2.5-dimensional numerical simulations. This study is focused on the cross-tail transversal mode, modeling the magnetotail flapping motions, at the background of the Kan-like magnetoplasma equilibrium. It is found that in symmetrical current sheets, both stable and unstable branches of the solution may coexist; the growth rate of the unstable mode is rather small, so that the sheet may be considered as stable at the substorm timescale. With the increasing dipole tilt angle, the sheet bends and the growth rate rises. For sufficiently large tilt angles, the stable branch of the solution disappears. Thereby, the sheet destabilization timescale shortens for an order of magnitude, down to several minutes. The analysis of the background parameters has shown that stability loss is not related to buoyancy; it is controlled by the cross-sheet distribution of the total pressure. © 2018 Author(s).

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Держатели документа:
Space Research Institute, Austrian Academy of Sciences, Graz, 8042, Austria
Earth Physics Department, Saint Petersburg State University, Petrodvoretz, 198504, Russian Federation
Institute of Computational Modelling, Siberian Branch, Russian Academy of Sciences, Krasnoyarsk, 660036, Russian Federation
Applied Mechanics Department, Siberian Federal University, Krasnoyarsk, 660041, Russian Federation
Theoretical Physics Division, Petersburg Nuclear Physics Institute, Gatchina, 188300, Russian Federation

Доп.точки доступа:
Korovinskiy, D. B.; Semenov, V. S.; Erkaev, N. V.; Ivanov, I. B.; Kiehas, S. A.